implement subroutine call and return

1 files changed, 8 insertions, 0 deletions

diff --git a/src/chip8.rs b/src/chip8.rs
index 83139f4..988dc6e 100644
--- a/src/chip8.rs
+++ b/src/chip8.rs
@@ -64,6 +64,8 @@ impl Chip8 {
                 }
                 0x000E => {
                     eprintln!("RET");
+                    self.sp -= 1;
+                    self.pc = self.stack[self.sp as usize];
                 }
                 _ => unknown_opcode(opcode),
             },
@@ -71,6 +73,12 @@ impl Chip8 {
                 eprintln!("JP {}", nnn);
                 self.pc = nnn;
             }
+            0x2000 => {
+                eprintln!("CALL {}", nnn);
+                self.stack[self.sp as usize] = self.pc;
+                self.sp += 1;
+                self.pc = nnn;
+            }
             0x3000 => {
                 eprintln!("SE V{}, {}", x, nn);
                 if self.v[x] == nn {